Bsi bs en 10226 3 2005

untitled BRITISH STANDARD BS EN 10226 3 2005 Pipe threads where pressure tight joints are made on the threads — Part 3 Verification by means of limit gauges The European Standard EN 10226 3 2005 has t[.]

Pipe threads where pressure-tight joints are made on the

This British Standard was

published under the authority

of the Standards Policy and

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Amendments issued since publication

EUROPÄISCHE NORM

ICS 21.040.30

English version

Pipes threads where pressure tight joint are made on the threads - Part 3: Verification by means of limit gauges

Filetage de tuyauteries pour raccordement avec étanchéité

par le filetage - Partie 3: Vérification par calibres à limites

Rohrgewinde für im Gewinde dichtende Verbindungen - Teil

3: Prüfung mit Grenzlehren

This European Standard was approved by CEN on 22 December 2004.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2005 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members.

Ref No EN 10226-3:2005: E

Contents

page

Foreword 3

1 Scope 4

2 Normative reference 4

3 Terms and definitions 4

4 Symbols 5

5 Design of gauges 6

5.1 General 6

5.2 Taper full form threaded plug gauges (gauges No 1 and No 2) 7

5.3 Parallel full form threaded ring gauge (gauge No 3) 11

5.4 Taper plain ring gauge (gauge No 4) 13

5.5 Taper modified thread form check plug gauge (gauge No 5) 14

5.6 Parallel modified thread form check ring gauge (gauge No 6) 16

6 Use of gauges and checking of pipe threads 18

6.1 General 18

6.2 Checking of internal taper (Rc) and internal parallel (Rp) threads 19

6.3 Checking of external taper (R) threads 20

7 Gauge dimensions and manufacturing tolerances, checking of new gauges and checking gauges for wear 21

7.1 Gauge dimensions and manufacturing tolerances 21

7.2 Checking of new gauges 28

7.3 Checking gauges for wear 31

7.4 Marking of gauges 33

Annex A (normative) Summary of gauges 34

Foreword

This document (EN 10226:2005) has been prepared by ECISS/TC 29 “Steel tubes and fittings for steel tubes”, the secretariat of which is held by UNI

This European Standard shall be given the status of a national standard, either by publication of an identical text or

by endorsement, at the latest by August 2005, and conflicting national standards shall be withdrawn at the latest by August 2005

This document is based, with editorial modification, on ISO 7-2: Pipe threads where pressure-tight joints are made

on the threads – Part 2: Verification by means of limit gauges

EN 10226 consists of the following parts, under the general title Pipe threads where pressure-tight joints are made

on the threads:

⎯ Part 1: Taper external threads and parallel internal threads - Dimensions, tolerances and designation

⎯ Part 2: Taper external threads and taper internal threads - Dimensions, tolerances and designation

⎯ Part 3: Verification by means of limit gauges

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

1 Scope

This document specifies a process using limit gauges, for the validation of taper internal and external threads and parallel internal threads on piping systems components and other products, the dimensions and tolerances of which are detailed in EN 10226-1 and prEN 10226-2

The gauging system described may not be suitable, without special precautions, for gauging of threads on injection moulded plastic workpieces

This document does not cover completely all the requirements necessary for full control of thread quality and dimensions Additional control of tools and equipment and visual inspection during production are required to ensure complete compliance with EN 10226-1 and prEN 10226-2, for example the length of useful thread on internally threaded workpieces should be checked by direct measurement

Annex A gives a summary of the gauges included in this document, together with details of the thread elements controlled by each gauge and gauge identification numbers

In the event of a dispute over compliance with the requirements of EN 10226-1 and prEN 10226-2, the gauges in this document are to be considered as decisive for the thread elements which they control on the workpiece

2 Normative reference

The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

EN 10226-1:2004, Pipe threads where pressure-tight joints are made on the threads — Part 1: Taper external threads and parallel internal threads — Dimensions, tolerances and designation.

prEN 10226-2:2002, Pipe threads where pressure-tight joints are made on the threads — Part 2: Taper external threads and taper internal threads — Dimensions, tolerances and designation.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 10226-1:2004 and prEN 10226-2:2002 and the following apply

accommodation length

distance from the face of an internally threaded workpiece to the first obstruction which the externally threaded workpiece will encounter on assembly

See Figure 3

4 Symbols

The symbols used and their explanations are given in Table 1

Table 1 — Symbols Symbol Explanation

b1 Width of clearance groove at major diameter of parallel full form threaded ring gauges and

minor diameter of taper full form threaded plug gauges

b2 Width of clearance groove at major diameter of parallel modified thread form check ring

gauges and at minor diameter of taper modified thread form check plug gauges

c Height of tolerance step on plug gauges

D Major diameter of internal thread at gauge plane

D1 Minor diameter of internal thread at gauge plane

D2 Pitch diameter of internal thread at gauge plane

D4 Counterbore diameter of parallel full form threaded ring gauge and taper plain ring gauge

d Major diameter of external thread at gauge plane

d1 Minor diameter of external thread at gauge plane

d2 Pitch diameter of external thread at gauge plane

F Radial distance from the pitch diameter to the truncated crest, along the centreline of the thread profile

l0 Overall length of taper full form threaded plug gauge and taper modified thread form check

plug gauge

l1 Length from end face to the gauge plane on taper full form threaded plug gauge

l2 Length of tolerance step on plug gauges

l3 Overall length of parallel full form threaded ring gauge, parallel modified thread form check

ring gauge and length from gauge plane to small end of taper plain ring gauge

l4 Length of tolerance step on ring gauges

l5 Depth of counterbore on parallel full form threaded ring gauge

l6 Overall length of taper full form threaded plug gauge with relief

l7 Width of relief on taper full form threaded plug gauge with relief

l8 Length from relief on taper full form threaded plug gauge with relief to large end of gauge

l9 Overall length of taper plain ring gauge

l10 Depth of counterbore on taper plain ring gauge

l11 Distance from step on gauge Nos 1 and 2 to face of gauge No 6 when verifying pitch

diameter of new gauge Nos 1 and 2

l12 Distance from step on gauge No 5 to face of gauge No 6 when verifying pitch diameter of

new gauge No 6

l13 Distance from step on gauge Nos 1 and 2 to face of gauge No 6 when checking pitch

diameter of gauge Nos 1 and 2 for wear

Table 1 (concluded)

Symbol Explanation

l14 Distance from step on gauge No 5 to face of gauge No 3 when checking pitch diameter of

gauge No 3 for wear

Tα 1/2 Tolerance on flank angle of full form threads

Tα 2/2 Tolerance on flank angle of modified form threads

TCP Tolerance on pitch diameter for taper modified thread form check plug gauge and parallel

modified thread form check ring gauge

TP Tolerance on pitch

TPL Tolerance on pitch diameter and wear allowance for taper full form threaded plug gauges

TR Tolerance on pitch diameter and wear allowance for parallel full form threaded ring gauge and

tolerance on diameter and wear allowance for taper plain ring gauge

T1 Tolerance on the gauge length of an external thread

T2 Tolerance on position of gauge plane on an internal thread

W Permissible wear on diameter of all gauges except taper modified thread form check plug gauges

NOTE The values of D, D1, D2, d, d1 and d2 shown in Table 2 to Table 7 are basic values and are subject to the manufacturing tolerances specified in Clause 7

5 Design of gauges

5.1 General

The taper full form threaded plug gauges and parallel full form threaded ring gauges (see 5.2 and 5.3) together with the taper plain ring gauges (see 5.4) have been chosen as representing the requirements for mating components

or products within the tolerances of EN 10226-1 and prEN 10226-2

Because of the 1:16 taper of the gauge and/or the threaded workpiece, it is possible to represent the maximum and minimum limits of diameter by means of tolerance steps within the axial length of the gauges

The plain ring gauges included in this document, allow a combined check of the major diameter and the length of useful thread of externally threaded workpieces

The taper modified thread form check plug gauge (see 5.5) and parallel modified thread form check ring gauge (see 5.6) for checking the manufacturing tolerances and wear allowances for the parallel full form threaded ring gauges and taper full form threaded plug gauges respectively, are made to a modified thread form

Some dimensions given in this document are more precise than the equivalent dimensions given in

EN 10226-1 and prEN 10226-2 This greater precision is only intended to assist the gauge manufacturing process and is of no practical significance when using the gauges

5.2 Taper full form threaded plug gauges (gauges No 1 and No 2)

5.2.1 Taper full form threaded plug gauge (gauge No 1)

This gauge is a 1:16 taper full form threaded plug gauge (see Figure 1) and is suitable for checking the major

diameter (D) and pitch diameter (D2) at the gauge plane of internal parallel (Rp) threads and internal taper (Rc) threads

5 Optional clearance groove (see 7.1.1.1)

6 The middle of the step face shall cut the thread flank at the pitch diameter

7 Clearance diameter

8 Pitch diameter

Figure 1 — Taper full form threaded plug gauge (gauge No 1)

The dimensions of this gauge are given in Table 2 and manufacturing tolerances are given in 7.1.1.2

The gauge incorporates a step equal in length to the total tolerance T2 on the position of the gauge plane of the internal thread specified in EN 10226-1 and prEN 10226-2 To allow for the chamfer on the internal thread, the step

is displaced by 0,5P relative to the gauge plane, such that the internally threaded workpiece can be verified with

reference to its face

The large diameter end face of the gauge is marked '+' (positive) and the face of the tolerance step is marked '–' (negative)

NOTE For sizes smaller than 1/2, the '+' and '–' markings may be omitted if not practicable

Table 2 — Dimensions of taper full form threaded plug gauge (gauge No 1)

Length from end face to the gauge plane

Length of tolerance step

Width of clearance groove

5.2.2 Taper full form threaded plug gauge with relief (gauge No 2)

This gauge is a 1:16 taper full form threaded plug gauge with relief of threads (see Figure 2) and is suitable for

checking the major diameter (D) and pitch diameter (D2) at the gauge plane, and the accommodation length (see Figure 3) of internal parallel (Rp) threads and internal taper (Rc) threads

5 Optional clearance groove (see 7.1.1.1)

6 The middle of the step face shall cut the thread flank at the pitch diameter

5 With free run-out

NOTE Figure 3 is applicable to internal parallel (Rp) threads and internal taper (Rc) threads

Figure 3 — Accommodation length

The dimensions of this gauge are given in Table 3 and manufacturing tolerances are given in 7.1.1.2

The gauge incorporates a step equal in length to the total tolerance T2 on the position of the gauge plane of the internal thread specified in EN 10226-1 and prEN 10226-2 To allow for the chamfer on the internal thread, the step

is displaced by 0,5P relative to the gauge plane, such that the internally threaded workpiece can be checked with

reference to its face On sizes 1/4 and larger, a thread relief is provided part way along the gauge, thereby reducing the number of threads and consequential friction in contact with the internally threaded workpiece

The overall length (l6) of the gauge is equal to the length of useful thread for maximum gauge length plus 0,5P.

The large diameter end face of the gauge is marked '+' (positive) and the face of the tolerance step is marked '–' (negative)

NOTE For sizes smaller than 1/2, the '+' and '–' markings may be omitted if not practicable

Table 3 — Dimensions of taper full form threaded plug gauge with relief (gauge No 2)

Length of tolerance step

Overall Length of gauge

Width of relief

Length from relief to large end of gauge

Width of clearance groove

Height of step

P d, D d2, D2 d1, D1 l1 l2 l6 l7 l8 b1

max.

c

1 2 3 4 5 6 7 8 9 10 11 12 1/16 0,907 7,723 7,142 6,561 1,588 2,268 7,823 — — 0,3 1,8

5.3 Parallel full form threaded ring gauge (gauge No 3)

This gauge is a parallel full form threaded ring gauge (see Figure 4) and is suitable for checking the minor diameter

(d1) and pitch diameter (d2) at the gauge plane of taper external (R) threads

Key

1 Face marked

2 Face marked

3 Gauge plane

4 Incomplete thread at each end of gauge shall be removed or chamfered (see 7.1.1.1)

5 Optional clearance groove (see 7.1.1.1)

6 Clearance diameter

Figure 4 — Parallel full form threaded ring gauge (gauge No 3)

The dimensions of this gauge are given in Table 4 and manufacturing tolerances are given in 7.1.1.2

The gauge incorporates a step equal to the total tolerance T1 on gauge length, specified in EN 10226-1 and prEN 10226-2 The step is situated between minimum and maximum gauge lengths measured from the gauge

plane and is counterbored for the diameter D4 to a depth l5

The gauge plane is located at the face of the gauge, opposite to the step

The overall length (l3) of the gauge corresponds to the maximum gauge length

The outer and inner faces of the tolerance step shall be marked '+' (positive) and '–' (negative) respectively

NOTE These signs indicate the maximum and minimum gauge lengths, respectively the corresponding minimum and maximum allowable diameters of the external thread

Table 4 — Dimensions of parallel full form threaded ring gauge (gauge No 3)

Diameter of counter- bore

Overall length of gauge

Length of tolerance step

Depth of counter- bore

5.4 Taper plain ring gauge (gauge No 4)

This gauge is a 1:16 taper plain ring gauge (see Figure 5) and is suitable for checking the major diameter (d) and

the related useful thread length on taper external (R) threads

Key

1 Face marked

2 Face marked

3 Gauge plane

Figure 5 — Taper plain ring gauge (gauge No 4)

The dimensions of this gauge are given in Table 5 and manufacturing tolerances are given in 7.1.2

The gauge incorporates a step equal in length to the total tolerance (T1 ) on gauge length, specified in EN 10226-1 and prEN 10226-2 The step is situated between minimum and maximum gauge lengths measured from the gauge plane

The overall length (l9) of the gauge corresponds to the length of useful thread for maximum gauge length

The small diameter end face of the gauge is marked '+' (positive) and the face of the tolerance step is marked '–' (negative)

NOTE These signs indicate the maximum and minimum gauge lengths, respectively the corresponding minimum and maximum allowable major diameters of the external thread

Table 5 — Dimensions of taper plain ring gauge (gauge No 4)

Dimensions in millimetres

Designation of

thread

Diameter at gauge plane

Diameter of counterbore

Length from gauge plane

to small end

of gauge

Length of tolerance step

Overall length

of gauge

Depth of counterbore

5.5 Taper modified thread form check plug gauge (gauge No 5)

This check plug gauge (see Figure 6) is used to check the dimensions of the parallel threaded ring gauge (gauge

No 3) when manufacturing the ring gauge and for checking the ring gauge for wear

Figure 6 — Taper modified thread form check plug gauge (gauge No 5)

The gauge is designed on the basis of the taper threaded plug gauge (gauge No 1) The tolerance step has been retained, but with respect to the gauge plane it is positioned entirely in the plus tolerance zone

The threads of the check plug gauge are truncated at the crests and provided with a clearance groove at the root of the thread in order to ensure the pitch diameters engage when gauging is carried out

The dimensions of this check plug gauge are given in Table 6

Table 6 — Dimensions of taper modified thread form check plug gauge (gauge No 5)

Height of step

Overall length

of gauge

Length of tolerance step

Radial distance from pitch diameter

5.6 Parallel modified thread form check ring gauge (gauge No 6)

This check ring gauge (see Figure 7) is provided to check the dimensions of the taper full form threaded plug gauges (gauge Nos 1 and 2) when manufacturing the plug gauges and for checking the plug gauges for wear

Key

1 Incomplete thread at each end of gauge shall be removed or chamfered (see 7.1.4.1)

2 This face marked to indicate position of gauge plane (see 5.6)

The gauge is designed on the basis of the parallel full form threaded ring gauge (gauge No 3) except that there is

no tolerance step

The threads of the check ring gauge are truncated at the crests and provided with a clearance groove at the root of the thread to ensure the pitch diameters engage when gauging is carried out

The dimensions of the check ring gauge are given in Table 7

One face of the gauge is marked to indicate the position of the gauge plane This marking shall be "Gauge plane"

or some other words or symbols agreed between the gauge manufacturer and the purchaser